I understand this feeling
and while on one hand...
installing any plugin is actually the responsibility of the person installing it.
There could be a better way of handling this so that one plugin install doesn't hose a full Moodle install..
Not as easy as it sounds, as there is the changes being made to the database..
But, your IT department should be able to get in to the backend of the Moodle install and rip out the corrupted plugin directory that is causing this problem..
this seems to the the quickest way to get your site back.. As trying to debug this can take for ever..
I have been through this a number of times on my development site when I am testing a new plugin I may want and or have been a little ambitious by rolling back my actual Moodle Version install to try out older plugins.
Getting back to the request for a better system for plugin checks..
it is a catch 22.. the powers that create could lock it down so only admin have that power.. which would save headaches.. then admins would have to be well versed in what they are about to do when they upgrade or add in a new plugin..